Use a long spout watering can or watering bottle to water.  Never spray succulents. 
If leaves are discolored, tear off easily, or are soggy to the touch the plant is overwatered.
If leaves are droopy or wrinkled the plant is underwatered.
Black spots or a white-ish hue indicates too much direct sun for the plant. 4 to 5 hours of sunlight preferred.
Change soil yearly.